body {
    width: 100%;
    min-width: 320px;
    max-width: 640px;
    margin: 0 auto;
    font-size: 14px;
    font-family: -apple-system,Helvetica,sans-serif;
    color: #666;
    line-height: 1.5;
}
*{
    -webkit-tap-highlight-color: transparent;
}
input {
    -webkit-appearance: none;
}
a{
    color: #666;
    text-decoration: none;
}
ul {
    margin: 0;
    padding: 0;
    list-style: none;
}
img {
    vertical-align: middle;
}
div {
    /* CSS3盒子模型 */
    box-sizing: border-box;
}
.app {
    height: 45px;
}
.app ul li {
    float: left;
    height: 45px;
    background-color: #333333;
     line-height: 45px;
    text-align: center;
    color: #fff;
}
.app ul li:nth-child(1) {
    width: 8%;
    
}
.app ul li:nth-child(1) img {
    width: 10px;
   
}
.app ul li:nth-child(2) {
    width: 10%;
}
.app ul li:nth-child(2) img {
    width: 30px;
    vertical-align: middle;
}
.app ul li:nth-child(3) {
    width: 57%;
}
.app ul li:nth-child(4) {
    width: 25%;
    background-color: #F63515;
}

/* 搜索 */
.search-wrap {
    position: fixed;
    overflow: hidden;
    width: 100%;
    height: 44px;
    min-width: 320px;
    max-width: 640px;
}
.search-btn {
    position: absolute;
    top: 0;
    left: 0;
    width: 40px;
    height: 44px;
}
.search-btn::before {
    content: "";
    display: block;
    width: 20px;
    height: 18px;
    background: url(../img/s-btn.png) no-repeat;
    background-size: 20px 18px;
    margin: 14px 0 0 15px;
}
.search-login {
    position: absolute;
    right: 0;
    top: 0;
    width: 40px;
    height: 44px;
   color: #fff;
   line-height: 44px;
}
.search {
    position: relative;
    height: 30px;
    background-color: #fff;
    margin: 0 50px;
    border-radius: 15px;
    margin-top: 7px ;
}

.jd-icon {
    width: 20px;
    height: 15px;
    position: absolute;
    top: 8px;
    left: 13px;
    background: url(../img/jd.png) no-repeat; 
    background-size: 20px 15px;
}
.jd-icon::after {
    content: "";
    position: absolute;
    right: -8px;
    top: 0;
    display: block;
    width: 1px;
    height: 15px;
    background-color: #ccc;
}
.sou {
    width: 18px;
    height: 15px;
    position: absolute;
    top: 8px;
    left: 50px;
    background: url(../img/jd-sprites.png) -81px 0;
    background-size: 200px auto;
}
.slider img {
    overflow: hidden;
    width: 100%;
}

/* 品牌 */
.brand {
    overflow: hidden;
    border-radius: 10px 10px 0 0;
}
.brand div{
    float: left;
    width: 33.33%;
}
.brand div img {
    width: 100%;
}
nav {
    padding-top: 5px;
}
nav a {
    float: left;
    width: 20%;
    text-align: center;
}
nav a img {
    width: 40px;
    margin: 10px 0;
}
nav a span {
    display: block;
}

/* 新闻 */
.news {
    margin-top: 20px;
}
.news img {
    width: 100%;
}
.news a {
    float: left;
    box-sizing: border-box;
}
.news a:nth-child(1) {
    width: 50%;
}
/* n+2就是从2个往后面选 */
.news a:nth-child(n+2){
    width: 25%;
    border-left: 1px solid #ccc;
}
